Tracheal intubation is one of several methods to secure the airway during resuscitation, being used especially when a protected airway is lacking. An example of guidelines for performing this is described on pages I-98-1-102 in Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.
Tracheal intubation is considered a difficult skill in general; See Wang et al “Preliminary experience with prospective, multi-centered evaluation of out-of-hospital endotracheal intubation” Resuscitation 58 (2003) 49-58. Insufficiently trained providers may cause complications to the victim during the procedure. The following complications are seen: Trauma to oropharynx, ventilation withheld for unacceptably long periods, delayed or withheld chest compressions, esophageal or right mainstem bronchial intubation, failure to secure the tube and failure to recognize misplacement of the tube.
One study by Wirtz et al, “Rate and Outcomes of Unrecognized Esophageal Placement of Endotracheal Tubes by Paramedics in an Urban Emergency Department”, Academic Emergency Medicine Volume 11, Number 5 591-592, found that esophageal intubation occurs in 10% of the cases, and right mainstem intubation occurs as frequently as in 18% of the cases. Esophageal intubation is associated with poor outcome, since lung ventilation is inhibited for extended periods of time.
Even with a correctly placed tube, tube dislodgement may happen while the patient is moved. In Wang et al 22 incidents of tube dislodgement were reported out of 742 intubated patients. Dislodgement is related to poorly securing of the tube, and may not be recognized by the paramedics.
The standard method for determining tube placement is auscultation. This is a difficult skill which needs regular practice to be sensitive. In the pre-hospital setting it is often complicated due to noise and motion.
End tidal CO2 detectors are also used, but this technique is not well suited for patients in cardiac arrest. Esophageal detector devices are also used. This is a balloon or syringe that is connected to the tube after intubation. The idea is that air can not be retracted from a tube in the esophagus. This is a separate device that represents extra cost and the procedure prevents compressions and ventilation from being delivered. Furthermore, there have been incidents where a esophageal detector device has sucked mucus into the tube, thereby falsely indicating wrong tube placement and preventing use of the tube. There is also a risk that vomit has entered the airways before intubation, and that vomit can occlude the tube, resulting in false positive detection from the esophageal detector device.